Subject: Re: randconfig build error with next-20150724, in mm/page_ext.c

From: Vladimir Davydov <[email-masked]>
Date: Fri, 24 Jul 2015 19:36:12 +0300

On Fri, Jul 24, 2015 at 09:27:53AM -0700, Jim Davis wrote:

> warning: (HWPOISON_INJECT && MEM_SOFT_DIRTY && IDLE_PAGE_TRACKING)
> selects PROC_PAGE_MONITOR which has unmet direct dependencies (PROC_FS
> && MMU)
> 
> mm/built-in.o: In function `page_ext_init_flatmem':
> (.init.text+0x30ef): undefined reference to `page_idle_ops'
> mm/built-in.o: In function `page_ext_init_flatmem':
> (.init.text+0x3172): undefined reference to `page_idle_ops'

This has already been reported by the kbuild test robot, see:

  [mmotm:master 260/385] warning: (HWPOISON_INJECT && ..) selects PROC_PAGE_MONITOR which has unmet direct dependencies (PROC_FS && ..)

It should be fixed by:

From: Vladimir Davydov <[email-masked]>
Subject: [PATCH] mm/Kconfig: fix IDLE_PAGE_TRACKING dependencies

Fixes: proc-add-kpageidle-file
Signed-off-by: Vladimir Davydov <[email-masked]>

diff --git a/mm/Kconfig b/mm/Kconfig
index db817e2c2ec8..a1de09926171 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -657,6 +657,7 @@ config DEFERRED_STRUCT_PAGE_INIT
 
 config IDLE_PAGE_TRACKING
 	bool "Enable idle page tracking"
+	depends on PROC_FS && MMU
 	select PROC_PAGE_MONITOR
 	select PAGE_EXTENSION if !64BIT
 	help